Bark stripping mechanism



April 4, 1967 Original Filed Aug. 2l, 1964 c. E. s'rRowlLaricsK 3,312,259

BARK STHIPPING MECHANISM 5 Sheets-Sheet 1 57 5' V "i 79 [n A@ /4 ff /2 k a #49 'I f/ a 4% @#6,

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E uw `f ATTORNEY;

April 4, 1967 c. E. sTRoMBEcK 3,312,259

BARK STRIPPING MECHANI SM original Filed Aug. 21, 19.64 3 sheets-sheet 2 Tgff?.

April 4, 1967 c. E. sTRoMBEcK BARK STRIPPING MECHANISM Original Filed Aug. 2l, 196.4

. 5 Sheets-Sheet 5 R m V m CARL E. STQOMBECK B AMI/4 QJ ATTOQNEYS United States Patent O 3,312,259 BARK STRIPPING MECHANISM Carl E. Strombeek, R0. BX 95, Loleta, Calif. 95551 @riginal application Aug. 21, 1964, Ser. No. 391,272, now Patent No. 3,245,444, dated Apr. 12, 1966. Divided and this application Feb. 14, 1966, Ser. No. 549,072 2 Claims. (Cl. 14A-311) This invention relates to the stripping of bark from logs, particularly redwood, and is in the present embodiment especially directed to means for converting existing types of fork lift mechanism of a tractor or similar heavy duty vehicle to rapid bark stripping service.

The present application is a division of my copending application Ser. No. 391,272, led on Aug. 21, 1964, now Patent No. 3,245,444, which is, in turn, :a continuation-inpart of my previous copending application Ser. No. 2,233,- 562, filed Oct, 29, 1962. In the lumber industry, particularly in the log handling operation, it is necessary to strip the bark from the logs, and frequently this is accomplished prior to delivery of the logs to the mill. More particularly, it is common practice to strip the bark from a log in the field by hand with the aid of a peeling-bar. Such field stripping of logs is advantageous in that the bark removed from the logs may be disposed of in the ield, as by burning, rather than occupying substantial storage areas of a mill prior to disposal. However, the hand stripping process is rather tedious and time consuming and many man hours are expended in stripping the logs in the field preparatory to shipment.

Advantages are of course to be gained where the bark stripping operation can be automated inasmuch as increased production rates of ciude logs can be achieved with a substantial reduction in man-hours. Therefore, various mechanical or hydraulic barkers have been developed which :are arranged to strip the bark from a log automatically. The mechanical type of barker may be likened to an extremely large lathe, means being provided to rotate the log while a cutting blade or the like is suitably fed into the bark. Hydraulic barkers are generally similar with the exception that high pressure water jets directed upon the rotating log are employed to effect bark removal in place of a mechanical cutter. In either case it will be appreciated that the barkers are not adapted to use in the field, and accordingly are located at a mill. As noted previously, this poses a problem in the disposal of the removed bark, and in fact requires long periods of stoppage to remove the stripped bark which clogs up the mechanism. Moreover, the initial investment for either of these types of automatic barkers is prohibitive except where huge volumes of logs are processed.

Accordingly, it is'an object of the present invention to provide a relatively inexpensive portable means forstripping bark from logs in the field in an automated manner.

Another object of the invention is to provide means for adapting the fork lift mechanism of a tractor or the like to `automated bark stripping service.

Yet another object of the invention is to provide a simple, economical attachment for a fork lift mechanism which facilitates a bark stripping action with the existing tilt and lift movements of the fork lift.

It is a further and more specific object of the invention to provide ya bladed shoe for attachment to the tine of a lift fork mounted on a powered tractor or the like whereby the shoe may be forceably wedged into the bark of a log and thereafter appropriately guided about the core of the log by the combination of the lift and tilt movements of the lift fork and the forward and backward and turning movement of the vehicle to strip sections of the bark from the core.

A still further object of the invention is the provision "ice of a stripping attachment for a fork lift which does not impair the normal operations thereof.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be set forth in the following description of the preferred form of the invention which is illustrated in the drawings accompanying and forming part of the specication. It is to be understood, however, that variations in the showing made by the said drawings and description may be adapted within the scope of the invention as set forth in the claims.

FIGURE 1 is a side elevational view of a track laying Vehicle having a fork lift mechanism modified in accordance with the present invention for bark stripping service, the modified fork lift being depicted in operable stripping relation to a log.

FIGURE 2 is a top plan view of the arrangement of FIGURE 1.

FIGURE 3 is a sectional view taken at 3-3 of FIG- URE 2, illustrating particularly a unique arrangement for attachment of a fork to the lift mechanism to facilitate log stripping service.

FIGURE 4 is a sectional view taken at line 4 4 of FIGURE 3, illustrating further the fork attachment depicted in FIGURE 3.

FIGURE 5 is a plan view on an enlarged scale of the stripping shoe attachment of the present invention as secured to the tine of a fork of the lift mechanism.

FIGURE 6 is a sectional view taken at line 6-6 of FIGURE 5.

FIGURE 7 is a sectional View taken at line 7-7 of FIGURE 5.

FIGURE 8 is a sectional View taken at line 8 8 of FIGURE 1, illustrating structural details of the shock absorbing mounting means employed in the securance of each fork to the lift mechanism to minimize breakage from impact during log stripping service.

FIGURE 9 is a plan view of a modified form of attachment for adapting a fork lift mechanism to log stripping service.

FIGURE 10 is a plan view of another modified form of bark stripping attachment in accordance with the invention.

FIGURE 11 is a plan view of still another modified form of the attachment.

Referring to FIGURE 1, 11 designates the fork lift mechanism of a tractor 12, or other vehicle. In fbasic respects the fork lift mechanism 11 is conventional, same having linkages for manually controlled, powered tilt and lift movements of a pair of lift forks 13, 14. More particularly, conventional pneumatic lift and tilt linkages 16 and 17 are provided on opposite sides of the vehicle 12 and secured to opposite ends of a cross beam 18 lat the front of the vehicle, and to which the lift forks are attached. Each lift linkage includes a lift arm 19 having a crank portion 21 pivotally connected as indicated at 22 to the corresponding side of the vehicle. A pneumatic cylinder 23 is pivotally secured at 24 to the side of the vehicle and has the free end of its piston rod 26 pivotally connected, as indicated at 27, to the elbow of the arm. Each tilt linkage, on the other hand, includes a tilt ann 28 having one end pivotally connected 1at 29 to an end of a crank arm 311, the opposite end of which is pivotally connected at 32 to the corresponding lift arm 19. A push and pull arm 33 has one end pivotally connected at 34 to an intermediate portion -of crank arm 31. The other end of arm 33 is pivotally connected, as indicated at 36, to one end of a K-crank 37, the opposite end of wh-ich is pivotally connected at 38 to the corresponding side of the vehicle. To complete the tilt linkage 17, a pneumatic cylinder 39 is pivotally connected at 41 to the side of the vehicle, and has the free end of its piston rod 42 pivotally connected at 43 to an intermediate portion of J-crank 37. The free ends of lift arm 19 and tilt arm 28 are interconnected by a cross link 44 pivotally connected at its opposite ends, yas indicated at 46 and 47, to the respective arms. It will =be appreciated that the cross links 44 interconnecting the ends of the respective lift and tilt arms 19 and 28 on the opposite sides of the vehicle 12 are pivotal upwardly and downwardly relative to pivots 22, and tiltable forwardly and rearwardly relative to pivots `47. Control of such movements is selectable in the conventional manner by lift and tilt levers 48 and 49 provided in the operators cab of the vehicle which are operatively associated with pneumatic cylinders 23, 39 for powering7 movements of the lift and tilt linkages 16 `and 17. The cross ybeam 1S is transversely secured between links 44, such that the selectively controlled lift and tilt movements just described are imparted to the beam, and therefore to the forks 13, 14 secured thereto. Additional movement of the entire fork lift mechanism longitudinally forwardly and rearwardly relative the tilt and lift axes is facilitated by forward and reverse movement of the vehicle selectively controllable by lever 51.

The selectively controllable movements of a conventional vehicle mounted fork lift mechanism as just described -are put to substantial diverse advantage in accordance with the basic concept of the present invention in the stripping of bark from a log in the field with a substantial saving in man-hours compared to existing log stripping methods. More specifically, -a stripping shoe 52 is provided for securance t-o the end of the tine of each fork 13 and 14. Each shoe is arranged such that upon forward movement of the vehicle, to impact the shoe carried by a fork into a log 53 (see FIGURES 1 and 2), the shoe penetrates the bark 54 off the log to the core 56 thereof. Then with the shoe embedded in the bark 54, the lift and tilt linkages 16 and 17 of the fork lift mechanism .11 are operated by manipulation of levers 4S and 49 and the vehicle is manipulated by lever 51 to successively position the forks and associated stripping shoes at a plurality of positions 52a, 52b, 52C, 52d which circumscribe in either circumferential direction over a portion of its circumference. In so doin-g, the shoe strips large sections of "bark from the log. It'will of course be appreciated that a continuous section of Ibark over the entire circumferential portion which the shoe is capable of traversing in a single position of the log is not necessarily removed in a single circumferential pass of the shoe. Accordingly numerous manipulations of the vehicle and fork lift mechanism yare usually required to remove such circumferential portion of the bark.

When the circumferential portion of bark is removed for one position of the log, it Ibecomes necessary to revolve the log to present another circumferential portion of bark to the stripping shoe. Such revolution of the log may be readily facilitated through the normal function of the fork lift mechanism. Accordingly it is `advantageous that the addition of the stripping shoe 52 to the forks 13, 14 does not impair the normal operation of the fork lift. The lift mechanism may then be readily employed to revolve a log through a fraction of its circumference to expose an additional portion of the lbark for stripping subsequent to removal of a previous circumferential portion of bark by the stripping shoe in coaction with the fork lift mechanism.

To the foregoing ends, each shoe 52 is preferably of substantially flat, rectangular lconfiguration Ias best shown in FIGURE 5. The leading transverse edge of the shoe relative to the longtiudinal axis of the fork tine to which 'it is secured is narrowed to define a cutting edge 57 (see FIGURE 6). It is particularly important to note that the shoe is preferably, although not necessarily, arranged for pivotal movement about a vertical axis through the tine. Such movement of the shoe enables the cutting edge 57 to assume a position substantially parallel to the log even though the fork lift carrying vehicle rams the shoe into a log from along ya vehicle approach axis which is offset from a perpendicular to the log axis (see FIG- URE 2). Such `an offset angle -of approach facilitates impaling of the log with only one of the two shoes secured to the `respective forks of the lift mechanism. All of the ramming force of the vehicle is accordingly concentrated at the one shoe, and a greater degree of bark penetration can accordingly be imparted thereto than would be provided were both shoes tosimultaneously impact the log. The advantageous pivotal movement of the shoe which facilitates positioning of the cutting edge 57 parallel to the log even under the foregoing circumstances is best facilitated by a pivot socket 5S (FIGURES 5, 6 and 7) which extends into the opposite edge 59 of the shoe and serves to receive the end of the tine. Preferably the socket is of symmetrical trapezoidal configuration in plan view with the base of the trapezoid coinciding with the edge 59 and oppositely inclined sides 61 extending into the shoe in symmetrical relation to its longitudinal axis. The tine is longitudinally centrally positioned within the socket such that the leading edge of the tine is spaced from the forward end of the socket and closely spaced from the inclined sides 61 thereof. A bolt 62 or equivalent pivot extends vertically through the shoe normal to its longitudinal axis and through the longitudinal axis of the tine positioned in the socket as just described. The head of the bolt resides in a counterbore 63 in the bottom of the shoe while a nut 64 secured to the opposite end of the bolt resides in a counterbore 66 in the top of the shoe. Such recessed positioning of the bolt head and nut is desirable so that no projections from the at upper and lower shoe surfaces lare provided which would impede normal fork lift operations. The inclined sides 61 of the socket of course facilitate limited pivotal move ment of the shoe relative to the tine, the sides of the socket determining the extent of pivotal movement of the shoe by engagement with the sides of the tine.

In addition to the cutting edge 57 provided at the leading transverse edge of the shoe, an additional cutting edge 67 is advantageously provided at least at one of the side edges thereof to facilitate a cutting action longitudinally of the log. Where only one side cutting edge is provided it is preferably at the outside edge rof the shoe as depicted in FIGURE 7.

It will be appreciated that by virtue of the numerous ramming manipulations of the shoe involved in the stripping operation, the fork lift mechanism is subjected to substantial repeated impact. Accordingly, it is desirable that the fork lift mechanism be appropriately modified to the end of better absorbing the impact forces. In this regard, the beam 18 preferably comprises upper and lower transverse cross rails 68, 69 interconnected by spaced vertical rails 71. The links 44 :are rigidly secured vertically between the transverse Irails 68, 69. The rails 68, 69 are formed with ridges 72, 73 along the forward portions of their upper and lower surfaces respectively. The shank of each fork is then provided with a rearwardly and upwardly projecting hook portion 74 yadjacent the fork elbow. Such hook portion is arranged to loosely engage the ridge 73V provided along the bottom surface of the lower rail 69. Similarly a rearwardly and downwardly projecting hook portion 76 is integrally provided with the fork shank at a position upwardly spaced from hook portion 74. Hook portion 76 is adapted to loosely engage the ridge 72 along the top surface of the upper rail 68. Either or both of the hook portions may be transversely enlarged as indicated at 78 (see FIGURE 3) to add girth to the forks at their points of engagement with the beam.

With the hook portions 76, 74 of a fork engaging the rims of the transverse rails 68, 69 of the beam, the forks may be slid to any desired transverse positions of the- Vbeam. More particularly, the forks are positioned such that their shanks are adjacent any desired ones of the vertical rails 71 of the beam. Shock absorbing clamp means are then employed to secure the shanks of the respective forks to the adjacent vertical rails of the beam. Preferably such clamp means, as best shown in FIG- URE 8 includes a U-band 79 which encompasses the leading face of a fork shank and the side faces of one of the vertical rails 71 of the beam. Slotted blots 81 or the like are secured to the ends of the parallel side portions of the band to project therefrom. The bolts traverse a bearing plate 82, which is disposed adjacent the rear face of the vertical rail, and are secu-red to nuts 83. It is particularly important to note that a sheet 84 of resilient material, such as rubber, is also traversed by the bolts 81 and interposed between the bearing plate and vertical rail. With the nuts cinched tight to engage the resilient sheet between the vertical rail and bearing plate thrust and twist forces generated upon impact yof a shoe with la log are absorbed to a large extent by the resilient sheet, rather than by the rigid members of the fork lift mechanism. Life of the lift mechanism is accordingly greatly extended.

Mounting of the forks on the beam may be :assisted if desired by the attachment of brackets 86 to the rails 68, 69 at positions of abutment with the shank of :a fork. The brackets serve to limit transverse movement of the forks along the beam.

Although it is desi-rable that stripping shoes be secured to the ends of a pair of opposed lift forks, where but one shoe is employed, the fork to which it is secured may be advantageously mounted centrally of the lift beam 18 as depicted in FIGURE 9. Desirably when `a single shoe is thus utilized, it is advisable that both side edges, las well as the leading edge of the shoe be formed as cutters to facilitate penetration in the bark.

As noted hereinbefore, pivotal movement of the stripping shoes facilitates positioning of the cutting edges thereof in a desired angular relation to a log reclining on the ground at any of a number of different angles of approach of the vehicle 12 to the log. Although this pivotal movement of the stripping shoes is effected in the embodiments previously described to a large extent by pivotal mounting of the shoes on the tines of the fork lift mech- -anism 11, and to a lesser extent by manipulation of the vehicle 12 to vary the `direction of advance thereof relative to the log, the same placement of the cutting edge of the shoe in desired angular relation to the log may be accomplished solely by slightly increased manipulation of the vehicle. More particularly, the stripping shoes may be mounted in a lixed position on the tines of the fork lift mechanism and reliance for pivotal movement of the shoes to place same in desired angular relation to the log be placed on manipulated turning movements of the vehicle. The shoes and vehicle thus pivot as an integral unit. The impact or force of the Vehicle is still employed to drive the cutting edge through the bark and the controllable lift and tilt movements of the fork lift mechanism 'are employed in conjunction with movements of the vehicle to strip bark from the log in the manner previously described. It will be understood that due to the weight of the log, it will usually remain stationary during the stripping operation.

FIGURE 10 illustrates one form of stripping shoe which may 'be secured lin fixed position to the tines of the fork lift mechanism 11 and manipulated in conjunction with movements of the vehicle 12 to strip bark from a reclining log 87 in .accordance with the present invention. More particularly, a shoe S8 is provided having a substantially rectangular configuration in plan View preferably defined by a linear trailing edge portion 89, parallel transversely spaced substantially linear side edge portions 91 in right angular relation to the rear edge and merging therewith at rounded corner portions 92, and a gently curving leading edge portion 93 extending between the side edge portions. The leading, side, and corner edge portions are sharpened to provide a continuous cutting edge extending substantially arcuately between opposite ends of the trailing edge portion of the shoe. Tlhe shoe is fixedly secured to the tines 13 of the lift mechanism 11 in transverse Ibridging relation thereto as by means of bolts 94, the side edge and corner portions 91, 92 being laterally displaced, and the leading edge portion 93 being forwardly displaced from the tines.

With the -shoe 88 provided as just described and xedly secured to the tines of the fork lift mechanism 11, the vehicle 12 is manipulated in the usual manner, by varying the relative speeds of the tracks on the opposite sides of the vehicle, to pivot and advance the vehicle toward the log -87 in a suitable direction to place the cutting edge of the shoe in a desired angular relation to the log. Preferably, the vehicle is manipulated to place the leading edge portion 93 substantially parallel to the log periphery as shown in FIGURE 10. Thus, instead of pivotal movement of a shoe relative to the tines being employed to place the cutting edge of the shoe in a desired angular relation to the log, in the instant embodiment reliance is placed upon pivotal movement of the vehicle for this purpose. Thereafter, the bark stripping process is conducted in the same manner as that for shoes pivotally mounted upon the tines. The impact of the vehicle is employed to drive the leading edge portion 93 of the `shoe through the bark, and manipulated tilt and lift movements of the fork lift mechanism in conjunction with the vehicle impact are effective in stripping the bark from the log.

Another form of -xedly mounted stripping shoe is depicted in FIGURE 1l, which permits advance of the vehicle toward the log with substantially any direction of attack, including ones nearly parallel to the log 87, while yet effecting placement of the cutting edge of the shoe in a desired angular relation to the log. More particularly, a shoe 96 having a substantially ellipsoidal (preferably circular) configuration in plan view with an outwardly projecting flange 97 is integral or iixedly secured to each tine 13 of the fork lift mechanism 11. The flange of each shoe is attached to the tine as by means of bolts 9S such that the curved edge of the shoe extends laterally and forwardly from the tine. The curved edge of each shoe is made to provide a cutting edge extending through substantially 360 degrees. By virtue of the substantial angular extent of the cutting edge of the shoe, the vehicle 12 may be manipulated to approach the log from substantially any direction and drive the cutting edge through the bark. Thereafter, the bark is stripped from the log by combined coordinated movements of the vehicle and fork lift mechanism in the manner previously described.

What is claimed is:

1. A method of stripping bark from logs reclining on the ground with a powered vehicle having a fork lift mechanism operatively mounted thereon including at least one fork with a portion projecting outwardly from the confines of the vehicle and means connected to the fork for selectively raising and lowering same and moving it inwardly or outwardly relative to the vehicle, comprising the steps of securing a bark stripping shoe to the outwardly projection portion of said fork Iin position to dispose a generally continuous peripheral cutting edge of the shoe with one portion thereof forwardly of said fork and 4arrother portion thereof laterally outwardly of said fork, manuipulating said vehicle to present a substantial portion of said cutting edge of said shoe against a reclining log 1n different positions of the vehicle relative to the log and drive said cutting edge into the bark of the log under the impact of said vehicle, and manipulating said fork lift mechanism to controllably raise and lower said fork while moving it inward-ly and outwardly relative to said log in correlation with manipulation of said vehicle to.

move it forwardly and rearwardly and thereby strip said bark from said log with said shoe.

2. A method of stripping bark from logs reclining on the ground with a powered vehicle having a fork lift 7 mechanism operatively mounted thereon including at least one fork with a portion projecting outwardly from the contines of the vehicle and means connected to the fork for selectively raising and lowering same and moving it inwardly or outwardly relative to the vehicle, comprising the steps of providing a cutting edge at the outwardly projecting portion of said fork with said cutting edge including a side bark cutting portion, manipulating said vehicle to present a substantial portion of said cutting edge 8 against a reclining log and driving said cutting edge into the bark of the log, and manipulating said fork lift mechanism and said vehicle to controllably raise and lower said fork while moving it along said log to thereby strip said bark from said log with said cutting edge. Y

No references cited.

DONALD R. SCHRAN, Primary Examiner. 

1. A METHOD OF STRIPPING BARK FROM LOGS RECLINING ON THE GROUND WITH A POWERED VEHICLE HAVING A FORK LIFT MECHANISM OPERATIVELY MOUNTED THEREON INCLUDING AT LEAST ONE FORK WITH A PORTION PROJECTING OUTWARDLY FROM THE CONFINES OF THE VEHICLE AND MEANS CONNECTED TO THE FORK FOR SELECTIVELY RAISING AND LOWERING SAME AND MOVING IT INWARDLY OR OUTWARDLY RELATIVE TO THE VEHICLE, COMPRISING THE STEPS OF SECURING A BARK STRIPPING SHOE TO THE OUTWARDLY PROJECTION PORTION OF SAID FORK IN POSITION TO DISPOSE A GENERALLY CONTINUOUS PERIPHERAL CUTTING EDGE OF THE SHOE WITH ONE PORTION THEREOF LATERALLY OUTWARDLY OF SAID FORK, OTHER PORTION THEREOF LATERALLY OUTWARDLY OF SAID FORK, MANIPULATING SAID VEHICLE TO PRESENT A SUBSTANTIAL PORTION OF SAID CUTTING EDGE OF SAID SHOE AGAINST A RECLINING LOG IN DIFFERENT POSITIONS OF THE VEHICLE RELATIVE TO THE LOG AND DRIVE SAID CUTTING EDGE INTO THE BARK OF THE LOG UNDER THE IMPACT OF SAID VEHICLE, AND MANIPULATING SAID FORK LIFT MECHANISM TO CONTROLLABLY RAISE AND LOWER SAID FORK WHILE MOVING IT INWARDLY AND OUTWARDLY RELATIVE TO SAID LOG IN CORRELATION WITH MANIPULATION OF SAID VEHICLE TO MOVE IT FORWARDLY AND REARWARDLY AND THEREBY STRIP SAID BARK FROM SAID LOG WITH SAID SHOE. 